Description

40 steel is used: for the manufacture of sheet metal, 1−2 mm 4−14 category, intended for cold forming; crankshafts, connecting rods, gear rims, flywheels, gears, bolts, axles and other parts after the improvement; shafts and extension shafts of the generators; medium sized workpieces, which are requirements of high surface hardness and high wear resistance at low strain (long shafts, chassis, rollers, gears) after surface hardening with heating HDTV; details of pipeline valves after quenching and tempering; hot-rolled strip profile with a bias for agricultural machinery; of forgings of shafts of compressors and gas turbines (steel 40A); the wire used for the manufacture of spokes of motorcycles and bicycles.

Fe is the basis. According to GOST 1050-88 and GOST 10702-78 the chemical composition is given for steel grade 40. According to GOST 1050-88, the nitrogen content is specified for the steel of the oxygen-converter method of smelting. For all other types of smelting, the nitrogen content was N≤0.008%. TU NZL 342-89 chemical composition is given for steel grade 40A.

Mechanical properties

Section, mm

t отпуска, °C

sT|s0,2, MPa

σU, MPa

d5, %

d4

d

d10

y, %

KCU, kJ/m2

HB, MPa

HRB

Tape flatted average strength of 0.1-4.0 mm according to GOST 10234-77 in the state of delivery (indicated delivery)

-

-

-

640-980

-

-

-

-

-

-

-

-

-

-

-

640-780

-

-

-

-

-

-

-

-

-

-

-

780-930

-

-

-

-

-

-

-

-

-

-

-

≤690

-

-

≥10

-

-

-

-

-

-

-

-

≤490

-

-

-

-

-

-

-

-

Rolled sheet 1-2 categories of heat-treated (annealing, normalization, high tempering or normalizing + tempering) in the delivery state according to GOST 4041-71

4-14

-

-

510-660

≥21

-

-

≥17

-

-

≤167

≤85

Wire for cold heading as supplied by GOST 5663-79

-

-

-

560-710

-

-

-

-

≥55

-

-

-

-

-

-

≤740

-

-

-

-

≥40

-

-

-

Hot-rolled steel and hot rolled with special surface finish

-

-

-

-

-

-

-

-

-

-

≤217

-

-

-

-

-

-

-

-

-

-

-

≤163

-

Steel calibrated and calibrated with special surface finish

-

-

-

-

-

-

-

-

-

-

≤217

-

-

-

-

≤590

-

-

-

-

-

-

≤197

-

Sheet

80

-

-

≥560

≥20

-

-

-

-

-

-

-

80

-

-

≥520

≥21

-

-

-

-

-

-

-

4-14

-

-

510-650

≥21

-

-

-

-

-

≤167

-

Tape

0.1-4

-

-

450-700

-

≥14

-

-

-

-

-

-

0.1-4

-

-

850-1050

-

-

-

-

-

-

-

-

Cold-rolled steel strip of 0.1-4.0 mm in the delivery state according to GOST 2284-79

-

-

-

690-1030

-

-

-

-

-

-

-

-

-

-

-

440-690

-

≥14

-

-

-

-

-

-

-

-

-

440-600

-

≥14

-

-

-

-

-

-

Steel grooved 5-th category

-

-

-

≥610

≥6

-

-

-

≥35

-

-

-

-

-

-

≥510

≥14

-

-

-

≥40

-

-

-

Forgings. Hardening + Vacation

300-500

-

≥275

≥530

≥15

-

-

-

≥32

≥290

156-197

-

500-800

-

≥275

≥530

≥13

-

-

-

≥30

≥290

156-197

-

100-300

-

≥315

≥570

≥14

-

-

-

≥35

≥340

167-207

-

100

-

≥345

≥590

≥18

-

-

-

≥45

≥590

174-217

-

Forgings. Normalization

300-500

-

≥215

≥430

≥18

-

-

-

≥40

≥440

123-167

-

500-800

-

≥215

≥430

≥16

-

-

-

≥35

≥390

123-167

-

100-300

-

≥245

≥470

≥19

-

-

-

≥42

≥390

143-179

-

300-500

-

≥245

≥470

≥17

-

-

-

≥35

≥340

143-179

-

100-300

-

≥275

≥530

≥17

-

-

-

≥38

≥340

156-197

-

100

-

≥275

≥530

≥20

-

-

-

≥40

≥440

156-197

-

Hot-rolled sheet in the delivery condition. Group strength К490В

≤2

-

-

490-720

-

≥12

-

-

-

-

-

-

2-3.9

-

-

490-720

-

≥13

-

-

-

-

-

-

Cold-rolled sheet in the delivery condition. Group strength К490В

≤2

-

-

490-720

-

≥13

-

-

-

-

-

-

2-3.9

-

-

490-720

-

≥14

-

-

-

-

-

-

Forged billet shafts of compressors and gas turbines, heat-treated in the delivery condition on the other NZL 342-89 (longitudinal samples, in the column of the delivery condition specified strength)

≤400

-

≥274

≥509

≥17

-

-

-

≥35

≥343

-

-

Rolled without heat treatment - delivery condition

60

-

-

≥570

≥20

-

-

-

-

-

-

-

6-25

-

-

≥570

≥19

-

-

-

≥45

-

-

-

80

-

≥340

≥580

≥19

-

-

-

≥45

≥589

-

-

-

-

≥340

≥600

≥16

-

-

-

-

-

-

-

-

-

≥320

≥580

≥17

-

-

-

-

-

-

-

Rolled steel and punching. Quenching in water from 830-850 °C (exposure for 2.5-4.0 hours depending on the thickness and weight of the workpiece) + Vacation

≤100

580-640

≥345

≥590

≥18

-

-

-

≥45

≥588

174-217

-

Rolled steel and punching. Annealing in air from 870-890 °C (exposure for 2.5-4.0 hours depending on the thickness and weight of the workpiece)

Start - 1250 °C, the end - of 800 °C. the cooling of the workpiece cross-section up to 400 mm in air.

Flock-sensitive sensitivity

not sensitive.

Machinability

In the hot rolled condition with a HB of 170 and blower SB=520 MPa Kn TV.SPL.=1.2 Kn b.St.=1.05

Surfacing

Surfacing of sealing surfaces of valves in accordance with OST 26-07-2028-81 is made by manual arc welding electrodes type e-20X13 with plaster SSSI-13НЖ, NII-48, NII-48Ж-1 or SV wire-12H13 or SV-20X13. Surface preparation for overlay welding is performed by machining. Surfacing is performed with preliminary and accompanying heating to 400-450 °C is not less than 3 layers with thickness not less than 4 mm, excluding allowance for machining. Heat treatment after welding is produced by tempering at 550-600 °C (delay of 2-5 h) hardness HB=301-350, at 600-650 °C (delay of 2-5 h) hardness HB=240 to 300, at 400-450 °C (delay of 2-5 h) hardness HB=351-400. The temperature of the furnace when loading the details for the home should be no more than 300 °C.